This device is surgically implanted to deliver mild electronic stimulation to muscles in a patient's upper airway during sleep, preventing any obstruction.Inspire Medical Systems

CLEVELAND, Ohio -- Millions of people in the United States who suffer from moderate to severe obstructive sleep apnea – a condition in which the upper airway collapses and closes off during sleep, causing repeated breathing disruptions – might one day have a new option beyond other therapies that are clunky or less effective.

A Phase 3 clinical trial conducted at University Hospitals Case Medical Center and 21 other locations in the U.S. and Europe tested the effectiveness of a device that is surgically implanted to deliver mild electronic stimulation therapy to the upper airway during sleep.

Researchers have found that the device, made by Minneapolis-based Inspire Medical Systems, is effective in reducing obstructive sleep apnea by restoring tone to the muscles that control the base of the tongue, preventing the tongue from collapsing and obstructing the airway during sleep. The stimulation is timed to each breathing cycle.

The new therapy is not meant to be the first line of defense against moderate to severe sleep apnea, but rather an alternative for people who can't tolerate wearing a mask with an air hose attached to a CPAP machine, says Dr. Kingman Strohl, a pulmonologist at University Hospitals Case Medical Center and professor of medicine at Case Western Reserve University School of Medicine.

Short for Continuous Positive Airway Pressure, CPAP blows air into a person’s nose forcefully enough to keep the back of the throat open.

Dr. Kingman StrohlUH

The Inspire therapy already has received provisional approval in Europe. Strohl says he is optimistic that the device will be approved by the Food and Drug Administration as well.

“This is a company that has experience and tradition with stimulus devices,” he said. “The components themselves are coming from FDA-approved [items].”

Left untreated, sleep apnea causes poor sleep quality, which can lead to weight gain, fatigue, depression and other decreases in quality of life. People with sleep apnea are at increased risk for other serious health complications such as heart disease and stroke.

Participants qualified for the clinical trial if they had moderate to severe sleep apnea and were unable or unwilling to tolerate CPAP therapy. They also had to have a body mass index (BMI) of less than 32.

One hundred and twenty-six patients, including seven at UH, met the strict enrollment criteria (including tonsil size) and had the device implanted during a two-hour surgical procedure.

Eighty-three percent of people enrolled were men. The mean age was 54.5 and the mean time from the diagnosis of obstructive sleep apnea to when the participants joined the study was 5.6 years.

View full sizeThis artist rendering illustrates how the upper-airway stimulation system therapy, created by Inspire Medical Systems, works.Inspire Medical Systems

After about a month of recovery, the device was activated and patients were able to modulate the amount of stimulation with a remote control. Over the course of 12 months, patients had five follow-up outpatient visits and a couple of overnight visits to the sleep laboratory for any adjustments to the device’s electrical stimulation.

Researchers were looking for two things: the apnea-hypopnea index (the number of apnea or hypopnea events per hour) and the oxygen desaturation index (the number of times per hour of sleep that the blood oxygen level drops by more than 4 percent).

They found that patients experienced substantial decline in the number of sleep interruptions one year following the implantation. At 12 months, the median AHI score decreased 68 percent and the ODI score decreased 70 percent.

At the end of the 12 months, 46 participants were randomly assigned to one of two groups. Half continued with the therapy for one week, while the other half stopped using the device. Those who stopped the therapy experienced a sharp rise in their median AHI score, along with snoring and fatigue.

CPAP is often considered the best treatment for sleep apnea. Strohl says it's the most predictable treatment for sleep apnea.

“About 40 percent take to CPAP like a duck takes to water,” he said. The rest either use it but don’t like it, plagued with self-esteem issues that come along with wearing a cumbersome mask – or they try it and quit.

“It can be vexing for the patient,” he said. “It requires a lot of education about it.”

Other therapies have followed CPAP. One, Provent, is placed on each nostril and applies pressure to open the airway. That therapy is most effective in people with mild to moderate sleep apnea.

All too often, though, patients who start using it stop because they don’t like how the mask looks or feels.

Another treatment, uvulopalatopharyngoplasty (UPPP for short), removes soft tissue from the back of the throat. The surgery often doesn’t succeed in significantly lowering the number of sleep events.

Christine Wirtz of North Olmsted was diagnosed with sleep apnea 10 years ago after her husband said her loud snoring caused him to retreat to the guest bedroom. Wirtz, 62, first had the UPPP surgery, then got CPAP, which she used for seven years. She didn’t like either therapy.

“You’re tethered to a machine with five feet of hose attached to your nose,” Wirtz said of CPAP. “It’s really not attractive.”

After hearing a radio ad for the clinical trial, she called to get more information. On Jan. 31, 2012 she had the surgery; the device was implanted under her right arm. Once it was activated, it didn’t take long for Wirtz to begin experiencing better sleep.

On the rare occasion that Wirtz forgets to turn the device on, she notices immediately. “I bolt up in bed, gasping [for air],” she said.

Study participants are being monitored for five years following their surgery. Wirtz is scheduled for her two-year checkup at the end of January.

“It’s made my quality of life better,” she said. “I hope to have it in me for the rest of my life.”

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